1. Field of the Invention
The present invention relates to image pickup units and image pickup apparatuses, and in particular, to an image pickup unit in which an image pickup device comprising a bare chip is bonded on an electric board and an image pickup apparatus including the image pickup unit.
2. Description of the Related Art
Electronic apparatuses, such as digital cameras, having the following structure are in practical, widespread use: A subject image based on light, which is reflected by a subject and passes through a photographic optical system, is formed on the light receiving surface of an image pickup device (e.g., a charge coupled device (CCD)), comprising a bare chip, disposed in a predetermined position and the subject image can be recorded as image data or the like in a predetermined format.
As an image pickup apparatus, such as a digital camera, there is an apparatus using an image pickup device comprising a bare chip, i.e., having a bare-chip mount structure.
For example, a cover glass is adhered on one surface of a flexible printed circuit board (FPC) using an adhesive. An image pickup device comprising a bare chip is connected to the other surface of the FPC through electrode pads and bumps. In this instance, the light receiving surface of the image pickup device is opposed to the cover glass.
The electrode pads and bumps are covered with an adhesive. Consequently, the FPC is bonded on the image pickup device by the adhesive, thus sealing the light receiving surface (image pickup area) of the image pickup device.
As described above, in the bare-chip mount structure, components, such as the bare chip (image pickup device) and the cover glass, each comprising a rigid plate material are fixed to the FPC comprising a flexible plate material using adhesive. The image pickup devices having the bare-chip mount structure are known.
Such a unitized device (image pickup unit) is incorporated into each of various electronic apparatuses, e.g., digital cameras. The unit provides an image pickup function of each apparatus.
In the above-described image pickup unit, the cover glass (light-transmissive material) is disposed in such a manner that the surface of the cover glass opposed to the image pickup device is in contact with the front surface of the image pickup unit. Thus, the image pickup device can be aligned with the image pickup unit in the direction along the optical axis of a lens unit with high accuracy.